An animal model of essential hypertension is being evolved using a physiologic bias (renal mass reduction and increased salt intake) synergized by food-schedule-induced adjunctive behavior. The physiologic bias is employed at a renal reduction amount and a salt level increase which by themselves are insufficient to induce a blood pressure increase. The reversibility of this form of hypertension will be evaluated by removing the behaviorally inducing conditions. Residual pathological changes will be examined.